Potential starter



H. A. STEEN.

POTENTIAL STARTER.

APPLICATION HLED MAR. 23, 1912.

Patented. An. 22, 1916.

2 SHEETSSHEET I,

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' H. A. STEEN.

POTENTIAL STARTER.

APPLICATION FILED MAFLZS, IQIZ. 1 1 95,5 26 Patented Aug. 22, 1916.

2 SHEETSSHEET 2.

il t all lg UNITED STATES PATENT OFFICE.

HALFDAN A. STEEN, OF NORWOOD, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO ALLIS-CHALMERS MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

POTENTIAL STARTER.

Specification of Letters Patent.

Patented Aug. 22, 1916.

To all whom it may concern.-

Be it known that I, HALFDAN A. STEEN, a subject of the King of Norway, residing at Norwood, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Potential Starters, of which the following is a full, clear, and exact specification.

This invention relates to potential starters and particularly to potential starters having means responsive to abnormal circuit conditions with time element attachments. In the operation of potential starters, it is desirable that such starters be moved into off position when in running position in response to abnormal circuit conditions. Such potential starters can be moved backward from starting position to off position without danger to the switch parts, but to avoid injury to the switch parts it is necessary that the starter or switch when in running position be moved forward to oil" position. In potential starters thus far manufactured the movable switch member has been thrown into off position upon the occurrence of abnormal circuit conditions without respect to the time that such abnormal circuit conditions have existed. This means that in potential starters thus far used it has been necessary to again actuate the potential starter through its starting and into its running position after the occurrence of every abnormal circuit condition.

It is therefore the object of my invention to improve potential starters and switches.

by providing them with an arrangement to prevent the opening of such starters or switches upon the occurrence of low or novoltage circuit conditions until or unless said abnormal circuit conditions have existed for a predetermined time.

The various novel features of my invention will be apparent from the specification.

line 2-2 of Fig. 1; and, Fig. 3 is a fragmentary elevation, similar to that shown in Flg. 1, with the parts shown in off position.

The details of the starting controller proper will not be fully described herein because they form no part of my present invention and are unnecessary to an understanding thereof,

The normal operation of the potential starter is substantially in the same direction, 'a movement through 180 forming a complete operation. The controller drum 10, which is immersed in oil in the tank 11, is moved by an operating handle 12 through a shaft 13 and gear wheels 14: and 15. The two opposite halves of the controller drum are identical in structure and each half cooperates in turn with each of two sets of contact fingers 16 during successive operations of the controller, the sets of contact fingers belng on opposite sides of the drum and arranged to simultaneously co-act with the two halves of the drum respectively. The stationary contacts 16 are mounted on an insulating support 17, which is located in the bottom of the stationary oil tank 11. The switch drum 10 with which these contact fingers cooperate is rotatably mounted in bearings 18 formed in the lower part of a large irregular shaped casting 19, which forms a portion of the cover for the oil tank, the remaining part 20 of the cover being of sheet metal and secured over the part 19. The shaft 13 upon which the handle and gear 14 are mounted is supported in another bearing portion of the irregular shaped casting 19.

Mounted upon the drum shaft 21 is a cam 22 upon which a roller 25 is adapted to ride. The roller is mounted in a casting 26 which is pivotally mounted on a rod 27 and which is provided with a finger 28 adapted to engage a stop29 forming a part of the casting 19. Secured to the finger 28 is one end of a spring 30, the other end of which is secured to a portion 31 of the casting 19 by a bolt 32. This spring 30 presses the roller 25 against the surface of the'cam under all conditions, biasing the movable switch member or drum to off position. Also secured to the drum shaft 21 is a catch 33 adapted, when the potential starter is in running position, to be held by a weighted latch 34 which is pivotally mounted on a rod 35 and which is provided with The latch 34- and arm 36 are integrally formed and connected by a sleev 37. By means of the latch the movable switch member is normally locked in running position.

A hammer 38, having a projection 39, and being pivotally mounted on a rod i0, is adapted to engage the arm 36 to disengage catch 33 and latch ill to permit the spring to throw the starter into off position. Bif ter striking the arm 36 the hammer 38 engages and rests on a padded stop 23. This hammer 38 forms the armature of a novoltage magnet having a core ll, forming a part of the casting 19, and a coil l2. The hammer 38 is moved into engagement with the core l1 by one of the rollers 61 being forced against the top of the hammer projection while the handle is turned from off to running position. \Vhen the magnet is energized it holds the hammer armature 38 against the core -l1. This hammer armature 38 tends to stay in engagement with the core 11 of the magnet even after the magnet is de'energized, this being due to the fact that the pivotal point it) is so located with respect to the center of gravity of the weighted armature 38 that said armature is in stable equilibrium when in engagement with the core ll. It is therefore seen that the armature 38 has a tendency to remain in engagement with the core 41 of the magnet both when the magnet is energized and deenergized. With no other provision being made for swinging the armature 38 about its pivotal point, the switch would remain in closed position during the continuance of abnormal circuit conditions. This would prove disastrous. But the armature member is so pivoted for the purpose of permitting low or no-voltage circuit conditions to exist for a certain predetermined time be fore tripping and opening the switch. Upon the occurrence of no-voltage or certain low voltage circuit conditions the armature hammer 38 is caused to move slowly about its pivotal point until its equilibrium has become unstable, whereupon, due to its own weight the armature rapidly passes into engagement with the arm 36 for the purpose above set forth. This initial slow movement of the armature 38 is effected by a time element attachment. This time element attachment preferably takes the form of a dash-pot the stationary member d3 of which is provided with a restricted opening it and a valve -15 which permits the es cape of air from and prevents the admis sion of air to the normally closed end of the dash-pot through said valve. This dashpot is also provided with a piston 46 having a rod 47 normally pressing against a lug -l8 on the armature 38. This piston 46 is biased in one direction by a spring 49 which an arm 36.

F has a tendency to gradually force the armature 38 out of its position of stable equilib rium. The spring a9 is backed by a plunger 50, the position of which is adapted to be changed by adjusting the nut 51 for the purpose of varying the efi'ectiveness of said spring, which, in other words, varies the time element. One end of the dash-pot is provided with a cap 52 through which the rod of the plunger passes. The piston rod l7 which is normally in engagement with the lug l8 of the armature 38, is not connected to the armature.

ll hen the potential starter or switch is in running position, the hammer 38 is held against the core ll of the magnet by the action of the current in the magnet coil 42 in addition to the normal bias of said armature due to the position of its pivotal point. The magnet is of suflicient strength to hold the armature in said position against the tension of the piston spring i9 which opposes the action of the magnet 42. lVith the controller in running position the parts are as shown in Fig. 1. If abnormal circuit conditions should arise, such as novoltage or certain low voltage circuit conditions, the magnet will become deenergized, but due to the fact that the armature 38 is in this normal position in stable equilibrium it will not fall immediately into engagement with the arm 36. However, the slow moving springpressed piston, through its rod 4-7, gradually forces or pushes the armature 38 away from the decnergized magnet about its pivotal point 40. If, within a certain predetermined time, that is, before the center of gravity of the magnet 38 has fallen to the left of its pivotal point 40, the circuit conditions should return to normal, the armature 38 would be drawn back into engagement with the core 4-1 against the action of spring T9 by the action of current in the magnet coil But if such abnormal circuit conditions should continue longer than said certain predetermined time, the center of gravity of the armature 38 will be shifted to the left of the pivotal point 40 and due to its weight the armature 38 will rapidly fly into engagement with the arm 36 for tripping the movable switch member, permitting said switch member to pass into off position. The time element may be made any desir able value by moving the piston plunger in one direction or the other. In addition to being automatically tripped, the movable switch member may be tripped manually by pressing the hand lever 03 which is connected to the latch 8st. lVhile this time element arrangement is particularly adapted for use in connection with potential starters, it can be used in connection with switches of all types which are responsive to low voltage or no-voltage circuit conditions.

There may be various modifications and arrangements other than that here shown LOU and described, and it is my intention to cover all such modifications and arrangements which do not depart from the spirit and scope of my invention as set forth in the appended claims.

What I claim as new is:

1. In a potential starter, the combination of a movable switch member, means for holding said switch member in a certain operative position, a pivotally mounted member normally biased in one direction by its own weight and another force, a slow acting device normally opposing movement of said pivotally mounted member in said direction and being effective upon the occurrence of no-voltage circuit conditions to actuate said pivotally mounted member to render said holding means inefiective.

2. In a potential starter, the combination of a switch member, a member for holding said switch member in a certain position, a pivotally mounted member being adapted to render said holding member ineffective, and a dash-pot device a movable element of which is associated with and disconnected from said pivotally mounted member, said dash-pot device being eflective upon the occurrence of low voltage circuit conditions to actuate said pivotally mounted member to render said holding means ineffective.

3. Ina potential starter, the combination of a movable switch member, means for holding said switch member in one position, means for rendering said holding means ineffective comprising a member held in one position by a normal bias due to gravity and a force that varies in response to the voltage of the circuit of the switch, and means operative on the occurrence of no-voltage circuit conditions for actuating said member to render the holding means ineffective.

4. In combination, a switch member, a latch for holding said switch member in one position, means for rendering said latch ineffective, said means comprising an electromagnet having an armature normally held inactive and out of engagement with said latch and biased to an inactive position, and means for actuating said armature to engage and trip said latch on the occurrence of abnormal circuit conditions.

5. In combination, a movable switch member, means for holding said switch member in a certain position, an electromagnet having an armature biased to and normally held in one position, means efiective on the occurrence of abnormal circuit condi tions for actuating said armature to engage and trip said latch, and means for retarding said actuating means while permitting unrestricted final movement of said armature whereby the latter may deliver a hammer blow in tripping said latch.

6. In combination, a movable switch element, means for holding said switch element in a certain position, means for rendering said holding means ineffective comprising a member normally held in inactive position by a normal bias and a force effective during normal circuit conditions of the switch circuit, means rendered effective on the occurrence of low voltage circuit conditions for actuating said member after said low voltage circuit conditions have existed for a predetermined time.

7. In combination, a movable switch member, means for holding said switch member in a certain position, means for releasing said holding means comprising an electromagnet having an armature biased to and held in inactive position during normal conditions in the circuit of said switch, and means for actuating said armature to release said holding means after abnormal circuit conditions have existed for a predetermined time while permitting unrestricted final movement of said armature to deliver a hammer blow in the release of said holding means, said actuating means comprising a dash pot device having a spring pressed and retarded actuating plunger.

8. In a retarded circuit breaker, a movable switch part biased to one position, means for holding said switch part in another position, means for releasing said holding means comprising an electromagnet provided with an armature cooperative with said holding means to actuate the same and biased to and held in an ineffective position during normal circuit conditions and means for rendering said armature eifective for actuation of said releasing means on the existence of abnormal circuit conditions for a predetermined time while permitting unrestricted movement of said armature on the termination of said time interval.

9. In combination, a movable switch element, means for holding said switch element in a certain position, means for rendering said holding means inefl' ective comprising a member mechanically independent of said holding means and biased to one position, and an electromagnet for holding said member in said latter position during the continuance of normal circuit conditions, means operative on the occurrence of abnormal circuit conditions for causing operation of said member to render said holding means ineffective, and means operative to retard said latter operating means for a definite time on the occurrence of said abnormal circuit conditions while permitting unrestricted final movement of said member.

10. In combination, a movable switch element, means for holding said switch element in a certain position, means for rendering said holding means ineffective comprising a member mechanically independent of said holding means and biased to one position, and an electromagnet for holding said memher in said latter position during the contindeliver a hammer blow to said holding 10 uance of normal circuit conditions, and means to render the latter ineffective.

means normally tending to move said mem- In testimony whereof I aflix my signature, her from said biased position and operative in the presence of two witnesses.

- on the occurrence of abnormal circuit con- Milwaukee, Wis, March 14, 1912.

ditions for causing efl'ective actuation of HALFDAN A. STEEN. said member after said abnormal conditions lvitnesses. have existed for a predetermined time to a LOUIS C. NICHOLS, position from which it falls by gravity to FRASER JEFFREY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

